1. Field of the Invention
The present disclosure relates to an optical colored glass, composition of the colored glass, and a preparing method of the glass, more particularly, to a glass composition containing Cu2ZnSnS4 and Cu2ZnSnSe4.
2. Description of the Related Art
Patents such as U.S. Pat. Nos. 3,806,349, 4,106,946, 5,091,115, and US20060270544 have disclosed the infrared transmitting colored glass. In U.S. Pat. No. 3,806,349, CdS, Se and Te are mixed in the glass composition. In U.S. Pat. No. 4,106,946, CdTe, ZnS, CdS, S and Se are mixed in the glass composition. In U.S. Pat. No. 5,091,115, CdS, CuCl and PbS are mixed in the glass composition. In US20060270544, CdO, and S+Se+Te are mixed in the glass composition. These glasses are characterized in adopting Pb- and Cd-based chalcogenide semiconductor compound thereof to adjust the color of the glass and light transmitting wavelength range of the glass. However, Pb- and Cd-based chalcogenide compound thereof is poison material for environment and human body.
Because Pb- and Cd-based chalcogenide compound thereof has poison for environment and human body, patent US20030123167 disclosed a Pb-free and Cd-free glass composition, but containing I-III-VI group semiconductor compound, monovalent I group element including Cu and Ag, trivalent III group element including Al, In and Ga, and hexavalent VI group element including S, Se, and Te. Such glass does not contain hazardous material, but Ag and In are precious metal and strategic material which are very expensive and not suitable for mass production of the optical glass.